float worldWidth = u.x - l.x;
float worldHeight = u.y - l.y;
float offset = 1f; //kleiner als world machen
BodyDef dymBodyDef = new BodyDef();
dymBodyDef.position = new Vec2(0 , 0 );
// dymBodyDef.position = new Vec2(worldWidth*0.5f , worldHeight*0.5f);
Body theBody = world.createBody(dymBodyDef);
EdgeChainDef myEdges = new EdgeChainDef();